Variable Portal blocks are simply used to pipe values from one location in your graph to another.
Variable Portalblocks are not essential, and are never actually necessary, since it would always be possible to link your data directly from a block's output to another block's input, without first passing the data through a
Variable Portalblock. The point of
Variable Portalblocks, then, is simply to keep your graph visually organized, and to prevent your dotted-line connections from crossing through areas of your graph that are already complicated, making things more confusing to look at. The following graph uses a Telegram bot to listen for the command "/maticprice", and to respond with a message containing Matic's price in whatever channel it heard the command:
Variable Portal blocks in this example are receiving references to the Telegram channel and Telegram bot that heard the command, and then passing those references along to the
Send Telegram Message block at the end of the graph, so that the reply is made by the same bot and in the same channel as the command occured.
Variable Portalblocks and instead pass that data directly from the
On Telegram Messageblocks to the
Send Telegram Messageblock. The consequence of this would be that those two dotted white lines would pass through the middle of all our other blocks, making our graph more visually confusing.